PSI - Issue 2_A

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com Sci ceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 2456–2462 Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2016) 000–000

www.elsevier.com/locate/procedia www.elsevier.com / locate / procedia www.elsevier.com / locate / procedia lsevier.com locate proce

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Peer review under responsibility of the Scientific Committee of ECF21. 10.1016/j.prostr.2016.06.307 ∗ Corresponding author. Tel.: + 33-5-57-04-40-00 ; fax: + 33-5-57-04-54-33. E-mail address: alexia.este@cea.fr 2452-3216 c 2016 The Auth rs. Publi hed by Elsevier B.V. e r-review under responsibil ty of the Scientific Committee of ECF21. ∗ Corresponding author. Tel.: + 33-5-57-04-40-00 ; fax: + 33-5-57-04-54-33. E-mail address: alexia.este@cea.fr 2452-3216 c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. E a l dress: 2452-3216 c 20 tee of ECF21. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. The deflection mechanism at an interface in brittle matrix composites plays an important role in the composite fracture mechanisms. With weak enough interfaces, a matrix crack can be stopped by a deflection mechanism which improves the composite toughness (Evans et al. (1991)). Thus, the analysis of crack deflection in ceramic composites has been widely investigated. In order to simulate the interface behavior, a finite element analysis has been proposed by Alfano and Crisfield (2001) using a damage law for interface elements. Cohesive zone models are extensively used to simulate interfacial damage and will then be considered as references. Di ff erent criteria have been proposed to predict a crack behavior at an interface between two materials under monotonic loading: the competition between deflection and penetration at the interface is analyzed. A criterion has * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt XV Portuguese Conference on Fracture, PCF 2016, 10-12 February 2016, Paço de Arcos, Portugal Thermo-mechanical modeling of a high pressure turbine blade of an airplane gas turbine engine P. Brandão a , V. Infante b , A.M. Deus c * a Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal b IDMEC, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal c CeFEMA, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal Abstract During their operation, modern aircraft engine components are subjected to increasingly demanding operating conditions, especially the high pressure turbine (HPT) blades. Such conditions cause these parts to undergo different types of time-dependent degradation, one of which is creep. A model using the finite element method (FEM) was developed, in order to be able to predict the creep behaviour of HPT blades. Flight data records (FDR) for a specific aircraft, provided by a commercial aviation company, were used to obtain thermal and mechanical data for three different flight cycles. In order to create the 3D model needed for the FEM analysis, a HPT blade scrap was scanned, and its chemical composition and material properties were obtained. The data that was gathered was fed into the FEM model and different simulations were run, first with a simplified 3D rectangular block shape, in order to better establish the model, and then with the real 3D mesh obtained from the blade scrap. The overall expected behaviour in terms of displacement was observed, in particular at the trailing edge of the blade. Therefore such a model can be useful in the goal of predicting turbine blade life, given a set of FDR data. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy A New Approach to Simulate Interface Damage in Brittle Matrix Composites Alexia Este a,b, ∗ , Bernard Toson a , Jacqueline Saliba b , Jalal El Yagoubi b , Jean-Christophe Mindeguia b , Eric Martin c , Ste´phane Morel b a CEA-CESTA, Le Barp, F-33114, France b Universite´ de Bordeaux, UMR 5295, Institut de Me´canique et d’Inge´nierie (I2M), Bordeaux, F-33000, France c Universite´ de Bordeaux, CNRS UMR 7190, Laboratoire des Composites Thermo-Structuraux (LCTS), Pessac, F-33600, France Abstract Under mechanical loading, brittle matrix composites develop various damage processes which include cracking of matrix and fiber / matrix interface. Cohesive zone models (CZM) are widely used to model interfacial damage. The aim of this paper is to propose an alternative approach based on a damage model associated to a di ff use meshing method. In this study, the deflection of a matrix crack at the fiber / matrix interface in a single fiber composite is simulated using CZM and the results are compared with those obtained with the new approach. The simulation of a te sile test (in the fiber direction) on a brittle single fiber composite is performed by using the damage model and the result show a g od agre ment with the reference one obtained with CZM. On this basis, it is shown that the damage model is able to r produc complex p enomenon as periodic matr x c ack defl ctions at the fiber / matrix int rface. c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibi ity of the Scientific Committee of ECF21. Keywords: damage, crack deflection, fiber / matrix interface, brittle matrix composites. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy A New Approach to Simulate Interface Damage in Brittle Matrix Composites Alexia Este a,b, ∗ , Bernard Toson a , Jacqueline Saliba b , Jalal El Yagoubi b , Jean-Christophe Mindeguia b , Eric Martin c , Ste´phane Morel b a CEA-CESTA, Le Barp, F-33114, France b Universite´ de Bordeaux, UMR 5295, Institut de Me´canique et d’Inge´nierie (I2M), Bordeaux, F-33000, France c Universite´ de Bordeaux, CNRS UMR 7190, Laboratoire des Composites Thermo-Structura x (LCTS), Pessac, F-33600, France Abstract Under mechanical loading, brittle matrix composites develop various damage processes which include cracking of matrix and fiber / matrix interface. Cohesive zone models (CZM) are widely used to model interfacial damage. The aim of this paper is to propose an alternative approach based on a damage model associated to a di ff use meshing method. In this study, the deflection of a matrix crack at the fiber / matrix interface in a single fiber composite is simulated using CZM and the results are compared with those obtained with the new approach. The simulation of a tensile test (in the fiber direction) on a brittle single fiber composite is performed by using the damage model and the result show a good agreement with the reference one obtained with CZM. On this basis, it is shown that the damage model is able to reproduce complex phenomenon as periodic matrix crack deflections at the fiber / matrix interface. c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: damage, crack deflection, fiber / matrix interface, brittle matrix composites. The deflection m chanism at an interface in brittle matrix composites plays an important role in the composite fracture mechanis s. With weak e ough interfaces, a matrix crack can be stopped by a deflection mechanism which improves the composite toughness (Evans et al. (1991)). Thus, the analysis of crack deflection in ceramic co posites has been widely investigated. In order to simulate the interface behavior, a finite element analysis has been proposed by Alfano and Crisfield (2001) using a damage law for interface elements. Cohesive zone models are extensively used to simulate interfacial damage and will then be considered as references. Di ff erent criteria have been proposed to predict a crack behavior at an interface between two materials under monotonic loading: t e competition between deflection and penetration at the interface is analyzed. A criterion has a,b, a b b Mindeg b c h b F u / r / lt show a good agreement with the reference one obtained with ZM asis, it is shown that the damage model is able to reproduce co x henome ctions at the fiber matrix int c 201 T n h Copyright © 2016 The Authors. ublishe by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons. rg/lice ses/by-nc-n /4.0/). P r view under esponsibility of the Scientific Committee of ECF21. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 1. Introduction 1. Introduction